Re: [support] Drupal 7 AHAH/AJAX issue

11 Sep 2012

      David,
Thanks a lot for your kind answer.
I had read about 'storage', I hope it was mentioned it is used in D6. In D7
it may work, probably they were discouraging to use it.

I have managed to do it using _SESSION stuff. Though it is working to some
extent, still I beleive I am missing certian things here. Request to
experts kindly review below code and guide me if I am correct.

For reference kindly see
http://www.netcloudsystems.com/?q=questionnaire/form/manage link.
Corresponding code is as below.  Please let me know, if below code is
correct, or it can be optimized for faster operation. I have two major
concerns,

1.   It looks to me the whole form is rebuilt when I click the "Add More
Caregories" button, hence it takes more time to add a question category. I
know it is happeing because I have a line of code  $form_state['rebuild'] =
TRUE; in add_more_categories function.

2. Next the sequence of calling of functions looks strange to me.
First time page loads, it calls questionnaire_my_form.
On clicking "Add More Categories" button, functions are called in below
sequence.

   - add_more_question_categories, category count = 1
   - questionnaire_my_form, category count = 2
   - questionnaire_category_callback, category count = 2

My understanding is that with AJAX, we should be able to modify the portion
of a form, not the whole form.
I am not able to acheive it.

Kindly somebody help me to understand D7 AJAX stuff better.

<?php
function questionnaire_menu() {
    $items = array();
    $items['questionnaire/form/manage'] = array(
        'title' => t('Manage questions'),
        'page callback' => 'questionnaire_form',
        'access arguments' => array('question manage'),
        'type' => MENU_SUGGESTED_ITEM,
    );
    return $items;
}
function questionnaire_permission()
{
    return array(
        'question manage' => array(
        'title' => t('Question management'),
        'description' => t('Provides question management capability'),
    ),
    );
}
function questionnaire_form()
{
    unset( $_SESSION['questionnaire']['all_categories'] );
    $_SESSION['questionnaire']['all_categories'] = 1;
    return drupal_get_form('questionnaire_my_form');
}
function questionnaire_my_form($form, &$form_state)
{
    $form_state['cache'] = TRUE;

    /////////////  Start question category ////////////

    $form['category_fieldset'] = array(
        '#tree' => TRUE,
        '#title' => t("Questions Categories"),
        '#prefix' => '<div id="category-div">',
        '#suffix' => '</div>',
        '#type' => 'fieldset',
        //'#description' => t('Please enter the question categories'),
       '#collapsible' => TRUE,
       '#collapsed' => FALSE,
    );
    for ($i=1; $i <= $_SESSION['questionnaire']['all_categories'] ; $i++)
    {
        if(isset($_SESSION['questionnaire'][$i-1]['catg']))
        {
            $form['category_fieldset'][$i]['catg'] = array(
                '#type' => 'textfield',
                '#title' => "Question Category $i",
                '#value' => $_SESSION['questionnaire'][$i-1]['catg'],
            );

            unset($_SESSION['questionnaire'][$i-1]['catg']);
            $form['category_fieldset'][$i]['remove'] = array(
                '#type' => 'checkbox',
                '#title' => 'Remove',
            );
        }
        else
        {
            $form['category_fieldset'][$i]['catg'] = array(
                '#type' => 'textfield',
                '#title' => "Question Category $i",
            );
            $form['category_fieldset'][$i]['remove'] = array(
                '#type' => 'checkbox',
                '#title' => 'Remove',
            );
        }

    }
    $form['category_fieldset']['add_more_categories'] = array(
        '#type' => 'submit',
        '#value' => t('Add More Categories'),
        '#submit' => array('add_more_question_categories'),
        '#ajax' => array(
        'callback' => 'questionnaire_category_callback',
        'wrapper' => 'category-div',
        'method' => 'replace',
        'effect' => 'fade',
    ),
    );
    /////////////  End question category ////////////

  $form['line_break1'] = array(
  '#markup' => '<br>',
  );
    $form['submit'] = array(
        '#type' => 'submit',
        '#value' => t('Save Questions & Categories'),
    );
    return $form;
}
function questionnaire_category_callback($form, $form_state)
{
    return $form['category_fieldset'];
}
function add_more_question_categories($form, &$form_state)
{
    //Here, loop through all the category elements, if any remove checkbox
is enabled, delete the corresponding row.
    $removed_categories = 0;
    $i = 0;
    $j = 0;
    while ($i < $_SESSION['questionnaire']['all_categories'])
    {
        if($form_state['values']['category_fieldset'][($i + 1)]['remove']
== 1)
        {
            $removed_categories++;
        }
        else
        {
            $_SESSION['questionnaire'][$j]['catg'] =
$form_state['values']['category_fieldset'][($i + 1)]['catg'];
            $j++;
        }

        $i++;
    }

    if($removed_categories > 0)
    {
        $_SESSION['questionnaire']['all_categories'] =
$_SESSION['questionnaire']['all_categories'] - $removed_categories;
    }
    else
    {
        $_SESSION['questionnaire']['all_categories'] =
$_SESSION['questionnaire']['all_categories'] + 1;
    }
    $form_state['rebuild'] = TRUE;
}
function questionnaire_submit($form, &$form_state)
{
    drupal_set_message('Save functionality not implemented yet.');
    $form['#redirect'] = FALSE;
}
?>

On Mon, Sep 10, 2012 at 9:01 PM, Metzler, David <metzlerd@evergreen.edu>wrote:
...
******
I have not used form values in this way before and am unsure if they will
work this way.  Typically $form_state[‘storage’] is where you might place
these values that are part the form that may be modified by ****ajax****callback handlers.  Have you tried using $form_state[‘storage’] instead of
$form_state[‘values’] for your $all_categories data?  ****
** **
** **
** **
 ------------------------------
*From:* support-bounces@drupal.org [mailto:support-bounces@drupal.org] *On
Behalf Of *Kamal Palei
*Sent:* Sunday, September 09, 2012 8:44 PM
*To:* **support@drupal.org**
*Subject:* [support] Drupal 7 AHAH/AJAX issue****
** **
Hi List****
I am trying to learn ****ajax**** stuff in Drupal 7.****
****
I want to have a simple questionnaire form. Where I will have a single
textfield.****
In that text field one will type a question category, and if he wants to
type more question categories, user need to click a  button "Add More
Categories".****
Please see link
http://www.netcloudsystems.com/?q=questionnaire/form/manage****
****
The whole source code is at the end of this email.  When ****ajax****callback fires, I want to remember how many textfields I need to add, so
that when a section of form is updated in _form() hook, I can according add
those many textfields.****
****
I am trying to manage that using a variable "$all_categories" and form
element $form['all_categories']  (of type value).****
****
I tried many options, always I find $all_categories value is 1.   So I am
unable to add more textfields. ****
My observation is whatever I set in ****ajax**** callback, in _form hook
api, I find value is lost.****
****
Kindly guide me what I am missing.****
****
Best Regards****
Kamal****
*NECS, Bangalore*****
****
****
*<?php*****
*function questionnaire_menu() {**
 $items = array();
$items['questionnaire/form/manage'] = array(
 'title' => t('Manage questions'),
 'page callback' => 'questionnaire_form',
 'access arguments' => array('question manage'),
 'type' => MENU_SUGGESTED_ITEM,
 );*****
*  return $items;**
}*****
*function questionnaire_permission() **
{
  return array(
   'question manage' => array(
   'title' => t('Question management'),
   'description' => t('Provides question management capability'),
   ),
  );
}*****
****
****
*function questionnaire_form() **
{
 return drupal_get_form('questionnaire_my_form');
}*****
****
****
*function questionnaire_my_form($form, &$form_state) **
{
  $form_state['cache'] = TRUE;
$all_categories = !empty($form_state['values']['all_categories']) ?
$form_state['values']['all_categories'] : 1;  *****
****
*  $form['all_categories'] = array(**
   '#type' => 'value',
   '#default_value' => $all_categories,
   '#value' => $all_categories);*****
****
*   // The prefix/suffix provide the div that we're replacing, named
by    **
   // #ajax['wrapper'] above.
   $form['category_fieldset'] = array(
        '#title' => t("Questions Categories"),
        '#prefix' => '<div id="category-div">',
        '#suffix' => '</div>',
        '#type' => 'fieldset',
        '#description' => t('Please enter the question categories'),
   );*****
*   for ($i=1; $i<= $all_categories ; $i++) **
   {
      $key = 'ctg' . $i;
      $form['category_fieldset']['category'][$key] = array(
         '#type' => 'textfield',
         '#title' => "Question category $i",
         );
    }  *****
*   $form['category_fieldset']['add_more_category'] = array(    **
        '#type' => 'submit',
        '#value' => t('Add More Categories'),
        '#ajax' => array(
          'callback' => 'questionnaire_category_callback',
          'wrapper' => 'category-div',
          'method' => 'replace',
          'effect' => 'fade',
          ),
     );
$form['submit'] = array(
        '#type' => 'submit',
        '#value' => t('Submit'),
        );
return $form;
}   *****
****
*function questionnaire_category_callback($form, &$form_state) **
{
  $form_state['values']['all_categories'] =
$form_state['values']['all_categories'] + 1;
  return $form['category_fieldset'];
}*****
****
*?>*****
****
Best Regards
Kamal
NECS, Bangalore
...
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